/*******************************************************************************************
 * Copyright (c) 2006-2009 Alex Robson, Rob Simmons, Craig Israel, and Rachel Twyford
 *
 * Use of this software in any form requires that you have both 
 * read and agreed to the following terms:
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions: 
 *
 * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice, 
 * this list of conditions and the following disclaimer in the 
 * documentation and/or other materials provided with the distribution.
 * Neither the name of Nvigorate nor the names of its contributors may 
 * be used to endorse or promote products derived from this software without 
 * specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED. IN NO EVENT SHALL ANY CONTRIBUTOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ****************************************************************************************/

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Reflection;
using Nvigorate.Common.Reflection;
using Nvigorate.Relational.Mapping.Index;
using Nvigorate.Relational.Mapping.Interface;
using Nvigorate.Relational.Record;
using Nvigorate.Relational.Repository;
using Nvigorate.Relational.Visitors;

namespace Nvigorate.Relational.Navigation
{
    public class DataReaderNavigator
    {
        protected IDataReader _reader;
        protected IRepositoryMapIndex _repositoryMapIndex;
        protected ILoadInstruction _instruction;
        protected Type _rootType;
        protected IResultVisitor Visitor { get; set; }
        protected List<ITargetRelationship> Relatives { get; set; }
        protected int _typeIndex = -1;
        
        protected IEnumerable<ITargetRelationship> GetRelatives(Type type)
        {
            var relatives = QueryBuilderHelper.GetRelatives(_repositoryMapIndex, type);
            return relatives
                .Where(relationship =>
                       _instruction.RecursiveLoad ||
                       _instruction.Properties.Contains(relationship.RelativeProperty) ||
                       _instruction.GetInstructionForType(relationship.RelativeType) != null

                );
        }

        public void Accept(IResultVisitor visitor)
        {
            Visitor = visitor;
            Traverse();
        }

        protected void Traverse()
        {
            IEnumerable<IRecord> records = ReaderRecord.GetRecords(_reader).Cast<IRecord>();
            Visitor.Visit(records, _typeIndex < 0 ? null : Relatives[_typeIndex]);

            if(_reader.NextResult())
            {
                _typeIndex++;
                Traverse();
            }
        }

        protected Type GetObjectType(PropertyInfo propertyInfo)
        {
            return Reflector.IsEnumerable(propertyInfo.PropertyType) ?
                                                                         propertyInfo.PropertyType.GetGenericArguments().First() :
                                                                                                                                     propertyInfo.PropertyType;

        }

        public DataReaderNavigator(Type type, IDataReader reader, List<ITargetRelationship> relationships)
        {
            _rootType = type;
            _reader = reader;
            Relatives = relationships;
        }
    }
}